Method for powering a spacecraft with extended-life battery operation

Abstract

A spacecraft, such as a satellite in geosynchronous orbit, is powered using at least two independently controllable batteries, such as lithium ion batteries, operably connected to the power-consuming components of the spacecraft. Each battery is operable in a higher-temperature range and inactivated in a lower-temperature range. The first battery and the second battery are operated in the higher-temperature range during a first period of time. The first battery is thereafter operated in the higher-temperature range during a second period of time, with the second battery being non-operational and in the lower-temperature range during the second period of time. The first battery and the second battery are thereafter operated in the higher-temperature range during a third period of time. The second battery is thereafter operated in the higher-temperature range during a fourth period of time, with the first battery being non-operational and in the lower-temperature range during the fourth period of time. The operable battery or batteries may be operated through a partial charging/discharging cycle. This alternating operation prolongs the lifetimes of the batteries.

What is claimed is: 
     
       1. A method for powering a spacecraft, comprising the steps of providing a spacecraft having power-consuming components therein;   providing in the spacecraft at least two independently controllable electrical storage batteries operably connected to the power-consuming components of the spacecraft, each battery being operable in a higher-temperature range and inactivated in a lower-temperature range, including a first battery and a second battery;   first operating both the first battery and the second battery in the higher-temperature range during a first period of time; thereafter   second operating the first battery in the higher-temperature range during a second period of time, the second battery being non-operational and in the lower-temperature range during the second period of time; thereafter   third operating both the first battery and the second battery in the higher-temperature range during a third period of time; and thereafter   fourth operating the second battery in the higher-temperature range during a fourth period of time, the first battery being non-operational and in the lower-temperature range during the fourth period of time.   
     
     
       2. The method of claim 1, wherein the first battery and the second battery are each lithium ion batteries. 
     
     
       3. The method of claim 1, wherein the higher-temperature range is from about 5° C. to about 15° C. 
     
     
       4. The method of claim 1, wherein the lower-temperature range is from about -30° C. to about -10° C. 
     
     
       5. The method of claim 1, including the additional step, after the step of fourth operating, of performing the sequence of steps of first operating, second operating, third operating, and fourth operating, in that order, at least one additional time.   
     
     
       6. The method of claim 1, wherein the first battery and the second battery each comprises: at least one electrochemical cell, and   a heater operable to controllably heat the electrochemical cell to the higher-temperature range.   
     
     
       7. The method of claim 1, wherein the first period of time and the third period of time are each about 11/2 months in duration. 
     
     
       8. The method of claim 1, wherein the second period of time and the fourth period of time are each about 41/2 months in duration. 
     
     
       9. The method of claim 1, wherein the first battery is operated through a partial charging/discharging cycle during the second period of time. 
     
     
       10. The method of claim 1, wherein the second battery is operated through a partial charging/discharging cycle during the fourth period of time. 
     
     
       11. The method of claim 1, wherein the spacecraft is in geosynchronous orbit about the earth. 
     
     
       12. A method for powering a spacecraft, comprising the steps of providing a spacecraft having at least two independently controllable electrical storage batteries operably connected to power-consuming components of the spacecraft, each battery being controllably activatable and controllably deactivatable, including a first battery and a second battery;   first operating both the first battery and the second battery during a first period of time with both batteries in an activated state; thereafter   second operating the first battery during a second period of time in the activated state, the second battery being in a deactivated state during the second period of time; thereafter   third operating both the first battery and the second battery during a third period of time with both batteries in the activated state; and thereafter   fourth operating the second battery during a fourth period of time in the activated state, the first battery being in the deactivated state during the fourth period of time.   
     
     
       13. The method of claim 12, wherein the first battery and the second battery are each lithium ion batteries. 
     
     
       14. The method of claim 12, including the additional step, after the step of fourth operating, of performing the sequence of steps of first operating, second operating, third operating, and fourth operating, in that order, at least one additional time.   
     
     
       15. The method of claim 12, wherein the first period of time and the third period of time are each about 11/2 months in duration. 
     
     
       16. The method of claim 12, wherein the second period of time and the fourth period of time are each about 41/2 months in duration. 
     
     
       17. The method of claim 12, wherein the first battery is operated through a partial charging/discharging cycle during the second period of time. 
     
     
       18. The method of claim 12, wherein the second battery is operated through a partial charging/discharging cycle during the fourth period of time. 
     
     
       19. The method of claim 12, wherein the spacecraft is in geosynchronous orbit about the earth.